Brain complexity: learning new tasks (Introduction)

by dhw, Tuesday, December 05, 2017, 13:45 (2545 days ago) @ David Turell

DAVID: I've taken the step of erasing all the back and forth to once again explain my theory about brain/skull enlargment which has been lost by you: Current evidence shows that a brain enlarges with new implementations and shrinks as it complexifies, all within the unchanging skull because of the cerebrospial fluid layer allows these modification of the brain. Ideas or concepts do not change brain size. I firmly believe this process antidates sapiens and goes back to orginial homo brains at all stages.

I agree with all of this, but pre-sapiens skulls, unlike ours, DID change - their brains expanded permanently. Whether their brains also shrank beforehand is speculation, but is perfectly reasonable. At each stage they would have followed this process until it could no longer implement new concepts, and then came the permanent expansion.

DAVID: I also believe that the development of more complex ideas can only be developed by more complex larger brains.

What do you mean by “development…developed”. You agreed earlier that the ideas are formed by the smaller brain. “If habilis has an idea for spears, the idea is immaterial. No brain change.” The implementation requires a larger brain, and so once the idea has been implemented “his brain has enlarged”. If it's habilis's spear you're talking about, then it would have been pre-habilis's idea. If it's habilis's new concept of a more complicated spear, then the implementation would lead to the next form of bigger-brained hominin - erectus maybe? I don't know enough about all the different hominins and hominids to offer a family tree - but it would be the same tree as in your own hypothesis.

DAVID: Thus the artifacts show the level of ideas and the level of implimentation related to that brain size. I firmly believe the evidence indicates size first, use second. I do not believe the appearance of new ideas cause expansion. Implementation can only come with the next larger size of brain, but that learning process will enlarge the brain….. (dhw’s bold)

I keep emphasizing that new ideas do not cause expansion. They come from the smaller brain, and the next size of brain is caused by the learning process (implementation), as you indicate here (in bold) and explained earlier: “Once he learns to knapp flint” etc. “his brain has enlarged”. The brain finishes enlarging when he has learned to make and use his spear, and not BEFORE. Make and use first, size second, as you have shown despite your firm belief in the opposite.

DAVID: ….which will shrink as the brain complexifies the new controls in the new neuron network, skull not changing.

The skull does not change in Homo sapiens! But it expanded in pre-sapiens! If the brain expanded beyond a certain limit, the skull had to expand to accommodate it until it reached a point (sapiens) when it stopped expanding, and complexification took over.

DAVID: We do agree that evolution builds on past developments of complexity by innovation. This theory follows that precept. And remember I'm using shorthand in writing, the role of soul being understood for brevity's sake.

My theory does indeed confirm that evolution builds on past developments. Each smaller brain comes up with new concepts for more complex artefacts, the implementation of which demands and produces a bigger brain. Your summary confirms every step described in your post of 2 December: concept first, brain expands through learning process (implementation) until we reach sapiens, when it stops expanding and complexification takes over. We remain in perfect agreement, except that you refuse to agree that we agree.